Side dump railway cars typically use a tilting bed which is raised on one side by air cylinders or the like so as to cause the contents of the car to slide out of the opposite side. As the bed is raised it is necessary to open the door on the low side to allow the contents to exit the car. Various prior art arrangements have been tried to accomplish this purpose but they are usually quite complex and therefore expensive. The present invention however, provides a door opening linkage which is straightforward and reliable and which can be contained completely in the area immediately below the tilt bed where it is well protected from the weather and relatively simple in design and inexpensive.